Smoke

[Scott Wood]

I was racing my mate the about a month ago, when i missed a gear going into 5th and just revved the arse off of it, bounced off the limiter and black smoke everywhere, car seemed alright still, and thought nothing of it. but the other day my mate told me that when i floor it and change gear i get a puff of black smoke out of the exhaust, is this anything to worry about? and how do i reslove it? the car doesnt smoke at all when im driving around normally though! any ideas?

 

[Captain Slarty]

are ya sure its black.. and not blue...

black is indicative of unburnt fuel (rich), blue is indicative of smokey oil...

possibly valve stem seals.. go down a long hill on the overun.. ie, throttle closed, then boost it at the bottom and look in yer mirror ?? any smoke.. ??

also, try a compression test, wet n dry... do a compression test on all 4 pots, note the readings, then repeat after adding about a teaspoon full of plain engine oil down the bores (via the plug hole).. if the readings increase, they usually indicate a worn bore or rings.. if they dont increase, great..

all readings should be roughly equal - should certainly be within 5-10 percent, preferably better. If you have bent a valve, then it will show in the comp readings as a low reading with no change on the wet test.

let me know the results.

Joe.

 

[Scott Wood]

Cheers mate ill try the less technical test tonight. i hvaent got a clue about engines! if it is the valve stem seals is this an expensive job?

 

[Captain Slarty]

it can be quite labour intensive. the cylinder head needs to be removed, completely stripped, and then reassembled and put back on.

Joe. - try the tests first -